I remember sailing at Carsington with Hoppy in big breeze where we sailed a high speed run with the t-foil uncleated completely... It was quite an unsual experience and the bow was very wayward!
As Will says, it took us probably 2 seasons of sailing the Badger to finally work out how much kicker and cunningham was 'enough', and to reach that amount you pull on as much as you can, then pull on a bit more, and then squat on the rack and wrap it round your hands and give it everything to pull on a bit more. You will be worried about pulling on enough, but to be honest the boat transforms and you can go so much faster upwind and in a lot more control as the boat drives forward in the gusts rather than trying to push you over.